Currently I am working on a project are using ASP.NET MVC, and I need reuse some user controls with Telerik Controls, As you know, many of those user controls for WebForm need enable ViewSate. So I had combined both new MVC and old WebForm pages in this project.and I had encountered and solved many issues both for integration and MVCI write some key points here as my collections and want to share with my visitors.Here is an article about adding MVC to regular website :link

3. Fix those weird problems of Visual Studio 2008 After copy the Classes such as "BaseUserControl.cs" to MVC project, whatever how many times I clean and rebuild the project, Those classes always can't be found by other classes.And another issue happen frequently is the Pages have using Telerik controls, always have error message 'Error Creating Control' at design time.After some research, I found those step will solve these issues like a magic.